Malignant Proliferating Trichilemmal Tumor of the Scalp: A Systematic Review

Abstract

Objectives: Malignant proliferating trichilemmal tumors of the scalp can exhibit aggressive presentation and recurrences. Our objective was to perform an evidence-based systematic review evaluating clinical presentation, tumor characteristics, and treatment modalities used to determine which treatment strategies had the best outcomes. Methods:The databases PubMed, Embase, and Cochrane Library were searched for relevant literature by the authors. Patient demographics, imaging, treatments, and other clinical characteristics were obtained. The results were reported using the Preferred Reporting Systems for Systematic Reviews and Meta-Analysis guidelines.Results: Thirty-nine studies with a total of 65 patients were identified. The most common presentation was a history of slowgrowing, painless swollen mass on the scalp. In total, 10 patients (15.4%) presented with spread to the regional lymph nodes and 6 (9.2%) additional patients presented with metastasis to distant locations. In total, 61 patients (93.8%) underwent surgery. Various chemotherapy and radiation therapy regimens were used. Of the 45 cases with documented follow-up, 11 (24.4%) patients had one or multiple instances of local, lymph node or metastatic tumor recurrence.Conclusions: Surgery is favored, and the exact approach should be based on clinical judgment. However, Mohs micrographic surgery should strongly be considered because of its superior margin control against such an invasive tumor. Radiotherapy and chemotherapy have been used as adjuvant therapy in aggressive cases or recurrence. Patients should be followed closely and examined often to frequently assess recurrence or metastasis. Randomized controlled trials are needed to further clarify these findings.

Malignant Proliferating Pilar Tumor

“…Other published reports have shown MPPT can behave in an aggressive manner, and can both locally recur and metastasize 3,5–9,22 . The rate of local recurrence (0%) and metastasis (6%; 1 of 17) of the MPPT in this study was lower than previously reported in both Ye et al 8 of 15% local recurrence in group 2 (low-grade MPPT) and 50% recurrence and/or metastasis in group 3 (high-grade MPPT) and in Osto et al 12 of 15.4% lymph node metastasis at presentation and 9.2% distant metastasis. However, Ye et al 8 also reports a meta-analysis of 185 cases from 8 series with a low rate of local recurrence (3.7%) and lymph node metastasis (1.2%).…”

Malignant proliferating trichilemmal tumor: a rare neoplasm in a rarer location. Case report and review of the literature

“…Moreover, p53 and Ki-67 markers in immunohistochemical examination are guiding in predicting the aggressiveness of the tumor (low grade-high grade). Decreased expression of p53, which is responsible for the repair of DNA damage, and increased expression of Ki-67, which indicates a high rate of mitosis in the cell, have been associated with malignant transformation and high recurrence rates (33)(34)(35). In a review of the literature, 93 well-documented cases of MPTTs were found, beyond our case (36)(37)(38)(39)(40)(41).…”

“…A guideline with a high level of evidence could not be established for their treatment since MPTTs are seen very rarely. According to most published paper surgery is favoured as gold standard, and the exact approach should be based on clinical judgment (35). Usually, surgical excision with a margin of 1 cm is the main step in the treatment of almost all MPTTs.…”

A rare ossifying trichilemmal cyst in a young female patient: Case report and literature review

“…Although most TCs are benign lesions, there are rare examples of TCs appearing malignancy [13][14][15]. In 2% of trichilemmal cysts, single or proliferating cells lead to tumours called proliferating trichilemmal cysts which may be locally aggressive [13][14][15]. Metastases to regional lymph nodes and distant organs have been rarely observed [13][14][15].…”

“…In 2% of trichilemmal cysts, single or proliferating cells lead to tumours called proliferating trichilemmal cysts which may be locally aggressive [13][14][15]. Metastases to regional lymph nodes and distant organs have been rarely observed [13][14][15]. Moreover, it is extremely rare for a trichilemmal cyst to be ossified [1,[5][6][7][8][9][10].…”